Posture cushion



FIG. 1 is a top, rear, and side perspective view of a posture cushion showing our new design.

FIG. 2 is a front elevational view thereof.

FIG. 3 is a side elevational view taken from the left of FIG. 2, the side opposite being a mirror image thereof.

FIG. 4 is a bottom plan view thereof, the top being a substantial mirror image of the bottom. 

The ornamental design for a posture cushion, as shown and described. 